Subject Index SummaryMedieval Warm Period (The World's Oceans): Although most studies of the Medieval Warm Period or MWP have been conducted over land, some have been conducted over various portions of the world's oceans; and since oceans cover a much greater percentage of the earth's surface than does good old terra firma, it is important to determine if the MWP was expressed over marine environments to the same degree that it was expressed over terrestrial surfaces. And the verdict is that it was.